Storage water heater units provide hot water to commercial and household facilities by heating stored water in a tank by electric elements or by a gas burner. After a unit ceases to function, the cause of failure is typically determined to be a water leak or similar fault. Such leaks often begin small, and if left unattended can develop into serious leaks that result in extensive water damage to the surrounding environment as well as to the appliance itself. Because of such a propensity for this type of failure and the high costs that are associated with it, there has been a substantial effort to enable the owner of a water heater unit to quickly determine the presence of a relatively small leak before it has developed into a serious problem.
Leak detection of water storage tanks has generally been accomplished through the use of moisture sensors located on or around the perimeter of the water storage tank. These sensors are activated in the presence of wet environments and can come in several different forms. However, depending on the number of sensors used and their location, a leak may go unnoticed for a substantial length of time as to result in permanent property damage. The moisture sensors may require a substantial accumulation of standing water in order to be triggered, meaning that a large amount of costly water damage can be incurred before a leak is first detected and action is taken to mitigate the problem. In addition, water storage tanks may be placed in a variety of environments where moisture sensors may be incompatible since optimal placement of the sensors may not be possible.
After a leak has been detected, varying degrees of response are offered by current leak detection systems. The simplest systems offer a passive response, whereby the system only provides an indicator (usually an audible or visible alarm) that a possible leak has been detected. Unfortunately, the leak indicators included on passive devices are generally local to the site of the water storage tank and do not allow for remote diagnostics. These systems are generally cheaper to purchase and install, although they offer a relatively small measure of protection against leaks and fairly limited notification utility. More advanced systems offer an active response, allowing for immediate action to automatically be taken when a leak is first detected. These active systems are connected to water line valves which can be closed in order to prevent additional water from entering the leaking portion of the system. However, active leak detection systems are more costly than their passive counterparts and require special hardware to install onto existing water system infrastructure.
It would be desirable to have a water leak detection system for a water heater unit storage tank that has a high sensitivity for detecting relatively small leaks, allowing a leak to be detected during its formative stages. In addition, the leak detection system should be compatible with both active and passive response equipment. Finally, the system should be amenable to a variety of water heater unit environments and be able to adapt to a variety of water heater unit designs and conditions. Preferably, the leak detection system should generally depend on characteristics of the water heater unit itself, and be able to take into account changes in these characteristics over the life of the water heater unit.